Silver has two stable isotopes with masses of 106.90509 u and 108.9047 u.The atomic weight of silver is 107.868 u.What is the percent abundance of each isotope? A) 50.0% ¹⁰⁷Ag and 50.0% ¹⁰⁹Ag B) 51.8% ¹⁰⁷Ag and 48.2% ¹⁰⁹Ag C) 55.4% ¹⁰⁷Ag and 44.6% ¹⁰⁹Ag D) 48.2% ¹⁰⁷Ag and 51.8% ¹⁰⁹Ag E) 44.6% ¹⁰⁷Ag and 55.4% ¹⁰⁹Ag

Question

Quizplus · Accepted Answer

Let x be the percent abundance of the isotope with mass 106.90509 u. Then the percent abundance of the isotope with mass 108.9047 u is 100-x. Using the atomic weight formula:

(106.90509 u)(x/100) + (108.9047 u)(100-x)/100 = 107.868 u

Solving for x, we get x= 51.8%. Therefore, the percent abundance of the isotope with mass 106.90509 u is 51.8%, and the percent abundance of the isotope with mass 108.9047 u is 48.2%. So, the best choice is B.

Silver Has Two Stable Isotopes with Masses of 106